Share-Based Compensation

3 Months Ended

Mar. 31, 2022

Share-based Payment Arrangement [Abstract]

Share-Based Compensation

Share-Based Compensation

The following table presents share-based compensation expense:

	For the Three Months Ended March 31,
	2021		2022
Share-based compensation	$	9.7	$	14.7
Tax benefit	2.2		1.7

As of December 31, 2021, the Company had unrecognized share-based compensation expense of $70.9 million. As of March 31, 2022, the Company had unrecognized share-based compensation expense of $105.3 million, which will be recognized over a weighted average period of approximately three years (assuming no forfeitures).

Restricted Stock

The following table summarizes transactions in the Company’s restricted stock units:

	Restricted Stock Units		Weighted Average Grant Date Value
Unvested units - December 31, 2021	1.1		$	95.03
Units granted	0.4		129.45
Units vested	(0.3)		108.92
Units forfeited	(0.0	)	94.04
Performance condition changes	0.0		139.30
Unvested units - March 31, 2022	1.2		102.84

For the three months ended March 31, 2021 and 2022, the Company granted restricted stock units with fair values of $26.7 million and $45.3 million, respectively. These restricted stock units were valued based on the closing price of the Company’s common stock on the grant date and the number of shares expected to vest. Restricted stock units containing vesting conditions generally require service over a period of three years to four years and may also require the satisfaction of certain performance conditions. For awards with performance conditions, the number of restricted stock units expected to vest may change over time depending upon the performance level achieved.

Stock Options

The following table summarizes transactions in the Company’s stock options:

	Stock Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)
Unexercised options outstanding - December 31, 2021	3.2		$	77.39
Options granted	0.0		129.17
Options exercised	—		—
Options forfeited	(0.0	)	197.79
Performance condition changes	0.0		139.31
Unexercised options outstanding - March 31, 2022	3.2		77.82		4.4
Exercisable at March 31, 2022	0.1		132.30		1.6

For the three months ended March 31, 2021 and 2022, the Company granted stock options with fair values of $0.8 million and $1.8 million, respectively. Stock options generally vest over a period of three years to five years and expire seven years after the grant date. All stock options have been granted with exercise prices equal to the closing price of the Company’s common stock on the grant date. Substantially all of the Company’s outstanding stock options contain both service and performance conditions. For awards with performance conditions, the number of stock options expected to vest may change over time depending upon the performance level achieved.

The weighted average fair value of options granted was $50.04 and $47.84, per option, for the three months ended March 31, 2021 and 2022, respectively. The Company uses the Black-Scholes option pricing model to determine the fair value of options. The weighted average grant date assumptions used to estimate the fair value of stock options granted were as follows:

	For the Three Months Ended March 31,
	2021		2022
Dividend yield	0.0	%	0.0	%
Expected volatility	37.6	%	36.8	%
Risk-free interest rate	1.0	%	1.7	%
Expected life of options (in years)	5.7		5.7
Forfeiture rate	—	%	—	%